Tobacco processing



Un i ds m atent TOBACCO PROCESSING Raymond R. Colton, 60 W. 68th St., and Irwin W. Scopp, 4 Stuyvesant Oval, both of New York, N.Y.

Filed Apr. 14, 1958, Ser. No. 728,047

7 Claims. (Cl. 131-140) No Drawing.

tures, usually artificially maintained by the burning of fuel, but also in the case of certain types of tobacco by the heat of the sun. During this operation the tobacco is brought within desired standards of quality which are closely associated with the color of the leaf. Substantially all of the moisture in the leaf and stems is dissipated by the heat. At the end of this operation the heat is discontinued and atmospheric air is permitted to circulate through the dried tobacco whereby an amount of moisture is restored to the product. Too little moisture is to be avoided since the dry leaves are brittle and cannot be handled without liability of breakage; too much moisture on the other hand will cause discoloration and spoilage of the product.

Following the initial heat treatment and partial restoration of moisture, the tobacco usually is subjected to an aging treatment. This involves a series of steps which vary according to the type of growth, ultimate form, i.e., Whether intended for pipe, cigar, cigarette, snuff, or chewing, and the various brand standards of each. Whereas, the initial curing of the leaf may be effected in a matter of days, the aging process, as carried out in the case of certain high grade tobaccos often extends over a period of several years.

In preparation for the aging operation the tobacco may be subjected to further moisture-and heat-processing. Thereafter it may be packed in hogsheads, and permitted to undergo natural processes of fermentation. This stage, like other steps in tobacco treatment requires expert attention with a view to maintaining favorable humidity requirements. Following aging, further moisture conditioning may be accomplished with or without the aid of temperature control. Thereafter blending of several types of aged tobacco may be accomplished, and the blended tobaccos may be subjected to further aging.

In order to condition the tobacco preparatory to the manufacturing operation, the moisture content should be carefully controlled. There are special reasons for accurate moisture control at this stage. The tobacco should posses a degree of pliability that will render it amenable to the mechanical operations to which it next will be sub jected, and, further, an exact proportion of moisture is required for the proper operation of automatic weighing and feeding machines. The amount of moisture now present in the product will largely determine that in the final manufactured article. Accordingly, it is known practice to add, at this stage in the process, a hygroscopic agent such as glycerol or diethylene glycol.

According to the present invention improvement in the stabilization and control of the moisture content of the tobacco is effected by the suitable employment of substances of the class of silicones.

By the term, silicones, we refer to that class of compositions generally comprehended thereunder. Since these constitute a class of compositions of known chemical and physical characteristics, theyneed only briefly be described here. It is understood that the silicones, commercially available, consist of compounds that are essentially polymeric organo-silicon compounds, characterized by the following elemental structure:

-tii-o In the foregoing formula, which may be regarded as the building block of the silicone series, R represents an alkyl or aryl organic radical, which is frequently but not exclusively methyl or phenyl. A complete description of the silicones may be found in numerous publications. See, for instance, McGregor, Silicones and Their Uses, 1954.

In the treatment of tobacco during processing, we find the silicone fluids to be quite suitable. These fluids are clear, colorless, tasteless, odorless and physiologically inert. Toxicological studies indicate that silicones are not irritating to the human skin and are harmless even in contact with the mucous membranes or taken internally. They cause no discernible ill effects when fed to test animals in doses as high as 2 percent of body weight. (V. K. Rowe et al, Journal of Industrial Hygiene, 30, No. 6, pp. 332-352; 1948.) In general, silicones have low thermal conductivity in comparison with alcohols and water.

We have found that the presence of silicones in tobacco products is highly desirable in effecting moisture control. The moisture content thereby may be stabilized at any desired level and during any step or steps of the processing and manufacturing operations. When the proper moisture content has been established, the treatment of the tobacco with the silicone inhibits evaporation of the contained moisture to the air, and repels moisture that would otherwise be taken up where the tobacco is exposed to a humid atmosphere. The processing of the tobacco thereby becomes substantially independent of vagaries of weather and atmospheric conditions, and avoidance of occasions of deleterious effects upon the tobacco, such as spoilage and discoloration, over a period of time and under unpredictable conditions that hitherto have caused difiiculty, is greatly facilitated.

While the silicone may be added to the tobacco at any stage during the processing where moisture control is desirable the use of silicone compounds is of special advantage preliminary to the mechanical manufacturing steps. It is particularly desirable'in carrying out automatic manufacturing stages to hold the weight per unit bulk of the tobacco within close limits in order that the machines may function properly, as above stated.

The silicone may be applied either as such or dissolved or dispersed in a suitable solvent or vehicle. If desired it may be admixed with other materials that hitherto have been added to tobacco such as agents to improve flavor, consistency and other desired properties of the product. The impregnation of the tobacco with the silicone may be effected by spraying, dipping, or other known methods.

Example To blended tobaccos which have been dried to a moisture content of 12 to 13 percent there is added 2 to 4 percent of a silcone fluid having a viscosity of centistokes at 25 C. The tobacco is then delivered to the shredding machines and reduced to a state of subdivision suitable for cigarette tobacco. After a relatively brief storage time the shredded tobacco impregnated with the silicone is transferred to the cigarettemaking-machines where itis fed at a controlled rate to the long strip of cigarette paper, rolled, out to cigarette length, inspected and packed.

The silicone fluid employed is-selected from the commercially available Dow Corning 200 fluids or from other commercial sources. It is understood that these fluids are not pure chemical compounds but are compositions of complex and variable type.

The silicone creates whatmay be regarded as a protective sheath that largely prevents either ingress or egress of moisture into or from the tobacco. The silicone subsequent to the application thereof may be removedif desired, but, inasmuch as silicone compounds are inert, tasteless, odorless, and harmless, they may be permitted to remain on the tobacco in the'manufactured product.

The term tobacco as herein used should be understood as being inclusive ofproducts, compositions, blends and miXtur'eswhich may be prepared not only from portions of the leaves ofthe plant, but also from selected portions of the stems, such as those knownas homogenized or reconstituted tobaccos.

Having now described our inventionfwh at we claim and desire to protect by Letters Patent is as'follows:

1. In the processing of tobacco, the improvement comprising incorporating with said tobacco a silicone during said processing, the amount of said silicone being sufii cient to reduce variations in the moisture content'of said tobacco.

'2. In-thepi'ocessingoftobacco, the improvement comprisingincorporating' withsaid tobaccoa silicone fluid during 'saidproae's'sing'tml amoamersaid' silicone fluid being suflicient' to rdtice variations in"the"moistu're con tent of said tobacco.

3. In the processing of tobacco, the improvement com prising incorporating with said tobacco a silicone fluid during said processing, said silicone fluid having a viscosity of 200 centistokes, the amount of said silicone fluid being suflicient to reduce variations in the moisture content of said tobacco.

4. In the processing of tobacco, the improvement comprising controlling the moisture content of the tobacco by incorporating with said tobaccoa" substantial amount of a silicone duringsaid processing, said amount of added-silicone being sufficient to reduce variations in the moisture content of said tobacco.

5. In the shredding of" tobacco, the improvement comprising incorporating with said tobacco prior to delivering said tobacco to the shredding means, a silicone, the amount of said silicone being sufficient to act as a lubricant during said shredding operation.

-6. In the processing of tobacco, the improvement comprising incorporating with said tobacco 2 to 4 perccntof a silicone during said processing.

7. In a method of processing tobacco andpreparing manufactured articles therefrom, the improvement comprising incorporating a silicone with said tobacco prior to the final steps in the manufacture thereof, the amount'of saidsilicone being sutficient to reduce variations inthe moisture contentof said tobacco.

References Cited in the file of thispatent UNIT-ED STATES PATENTS 7 REFERENCES liodel lingineering; d ebruary E132:ges 5234. 

1. IN THE PROCESSING OF TOBACCO, THE IMPROVEMENT COMPRISING INCORPORATING WITH SAID TOBACCO A SILICONE DURING SAID PROCESSING, THE AMOUNT OF SAID SILICONE BEING SUFFICIENT TO REDUCE VARIATIONS IN THE MOISTURE CONTENT OF SAID TOBACCO. 